Although the author of over 50 books and 50 screenplays, with more than 400 short stories to his credit, Robert Bloch was haunted by being known as "the author of Psycho". The blurb appeared on most of Bloch's books including his last novel, Lori (1989), even though Psycho had been published 30 years before.

Bloch, regarded by many as one of the great writers of modern psychological horror, believed that unseen terrors were more effective in horror writing than labouring over the graphic detail. In his writing, the result of the knife- or axe- blow was implied, never described.

Fond of comedy, he would often adopt a comic persona when addressing fantasy writing conventions. The British horror writer Ramsey Campbell once said of Bloch that he was the best stand-up act since Boris Karloff in Frankenstein. Bloch claimed that he constructed his plots around a nasty punch-line or pun. The critic Jack Sullivan believed that the "sick joke" element in Bloch's writing sustained his popularity in the United States through the eras of Vietnam and Watergate.

Bloch was born in Chicago in 1917. His parents were poor, nonorthodox Jews of German descent. Although encouraged to read from an early age by his mother, Bloch got his first taste for the horror genre from film. He loved the cinema, and claimed to have seen the 1925 silent version of The Phantom of The Opera, starring Lon Chaney, when only eight years old. The film affected him deeply. He loved the sensation of terror that lingered afterwards and which, in this case, gave him two years of recurrent nightmares.

In 1927 Bloch discovered his first horror magazine, the August issue of the renowned classic Weird Tales, in the local railway depot. His aunt, who argued over his choice, bought it for him with some reluctance (the covers, by Hugh Rankin, often showed cartoon semi-clad girls wrestling with monsters). At the age of 15 he wrote a "fan letter" to one of the Weird Tales contributors, the classic horror author H. P. Lovecraft. For reasons which Bloch never understood, Lovecraft encouraged the correspondence, offering to lend him copies of books from his private library.

During his last year in high school, Bloch rented a typewriter and started to write his own fantastic tales. Encouraged by Lovecraft (with whom he continued to correspond), he submitted these to various magazines. In 1934 Farnsworth Wright, the editor of Weird Tales, bought four of his stories for $100. It was at this point that Bloch made the decision to become a professional writer.

He had started his writing career by imitating his mentor, and produced pastiches of Lovecraft's Chthulu Mythos world. "The Shambler from the Stars" (1935) features a strange character from Providence (the town where Lovecraft lived), who meets a gruesome end at the hands of a night creature. The character is of course Lovecraft, and this joke on Lovecraft is only one of the many examples of Bloch's bizarre sense of humour. (Lovecraft included a victim with the name of Robert Blake in his own story "The Haunter of the Dark"- thus returning the compliment.)

In 1940 Bloch married Marion Holcombe. Their daughter Sally was born two years afterwards and Bloch started work with the Gustav Marx Advertising Agency, of Milwaukee. He wrote fiction while working full-time with the agency, continuing to be published by Weird Tales, to growing acclaim.

In 1944 he was asked to write 39 episodes of a radio horror show called Stay Tuned for Terror. A year later August Derleth's Arkham House, Lovecraft's publisher, published Bloch's first collection of short stories, The Opener of the Way. At the same time, his best- known early tale, "Yours Truly, Jack the Ripper", received considerable attention through readings on radio and republication in anthologies. This story was the foundation on which Bloch built his reputation for a concern with inner horror rather than the external world of strange creatures.

Encouraged by the success of "Yours Truly, Jack The Ripper", Bloch wrote his first novel The Scarf (1947). This moved away from the supernatural, being a first-person account by a psychopathic strangler.

In 1953 Bloch left the advertising agency to return to writing full-time. He continued the crime theme in another novel, The Kidnapper (1954). This was the story of a kidnapping told from the protagonist's point of view. The viewpoints of both The Scarf and The Kidnapper were considered quite shocking and unusual at the time, although several psychologists applauded the medical accuracy of Bloch's insight, even recommending the novels as case studies.

With the demise of Weird Tales, Bloch continued to have his fantastic fiction published in Amazing, Fantastic and Fantastic Universe. His output of thrillers increased and he began to appear regularly in The Saint, Ellery Queen and similar mystery magazines.

Bloch won the prestigious SF Hugo award in 1959, the same year that Psycho was published. Developed from an earlier short story entitled "Lucy Comes to Stay", Psycho was loosely based on the real-life murder case of the serial killer Ed Gein, about whom Bloch later wrote an article, "The Shambles of Ed Gein". Psycho's immortality was guaranteed when Alfred Hitchcock filmed the novel with a screenplay by Joseph Stefano in 1960. Starring Anthony Perkins as Norman Bates, the film features the infamous shower murder scene with the actress Janet Leigh.

Even though the film significantly boosted his book sales, Bloch was already enjoying considerable success, particularly in film and television. During the next 10 years he wrote for numerous American television series: Alfred Hitchcock Presents, Thriller, Night Gallery and even Star Trek, as well as collaborating with the horror film "showman" William Castle, writing the screenplay for Straitjacket (1963). The producers Milton Subotsky and Max Rosenberg commissioned Bloch to adapt several of his short stories for a series of film horror quartets - Torture Garden (1967), The House that Dripped Blood (1970) and Asylum (1972) - based on the old Ealing Studios "Dead of Night" formula of linked tales of terror.

In 1975 Bloch was presented with a Lifetime Achievement Award at the first World Fantasy Convention held, appropriately, in Providence. The award was a bust of H. P. Lovecraft. His later short- story collections included Mysteries of the Worm (1981) and Midnight Pleasures (1987). In February 1991 he was given the Honour of Master of Ceremonies at the very first World Horror Convention held in Nashville, Tennessee. Last year he published his autobiography, One More Story to Tell.

Robert Bloch was respected and loved by his peers, and enjoyed a great reputation for kindness. He was also well known for outrageously corny jokes. He would reputedly invite visitors to his office with the assurance that although he wrote horror fiction he "had the heart of a little boy". And, "If they wanted, he would even let them pick it up and hold it."